Cancer is a disease characterised by uncontrolled cell growth caused by accumulation of genetic mutations in the cellular DNA. There are over 200 types of different cancer classified according to the cell of origin from which the cancer or tumour first developed. Furthermore, cancers can be classified broadly as either solid tumours, for example breast cancer, colorectal cancer and melanoma, or as haematological malignancies such as leukaemias and lymphomas.
Solid tumours typically initiate and grow as an abnormal mass at a local site. However, during the course of cancer progression, the cells may acquire the ability to invade the underlying tissue and thereby enter the circulatory and/or lymphatic systems. These invasive properties ultimately allow solid tumours to metastasise to distal sites within the body, and it is metastasis combined with growth at secondary sites that accounts for the vast majority of cancer deaths.
In contrast to solid tumours, cancers such as leukaemias and lymphomas derive from cells of haematological origin, and therefore manifest as systemic diseases. In particular, chronic lymphocytic leukaemia, the most common form of leukaemia, develops from malignant lymphocytes originating in the bone marrow.
The body has many intrinsic mechanisms intended to guard against cancer development. In this regard, the immune system is thought to play a key role in eradicating cells harbouring genetic mutations. It follows therefore, that cancer cells often persist by evolving ways to avoid recognition by the cells of the immune system. In particular, it has been shown that elevated levels of T regulatory cells, both within the peripheral circulation and within the tumour microenvironment, underlie the immune suppression seen in cancer patients. The presence of increased numbers of regulatory T cells has also been identified as a barrier to the successful implementation of cancer immunotherapies.
Apheresis is a treatment used for depletion of blood components, such as antibodies, low-density lipoproteins (LDL) and blood cells. Leukapheresis is the apheresis treatment used for removal of white blood cells, leukocytes. The patient is connected to an extracorporeal blood circulating system; the blood is drawn from a vein in one arm, passed through a column device and returned into the other arm of the patient. WO2010/029317 describes apheresis columns useful for treating inflammatory conditions including a chemokine immobilised on a solid support.